Process of preparing etched or engraved plates.



B. JONES.

PROCESS 0F PREPAR'ING ETCHED 0R ENGRAVED PLATES.

APPLICATION FILED APR.20. I9I6.

vrammed Aw. 20, 1918.

/MQUQ /MM BUBGOYNE JONES, 0F HINSDALE, ILLINOIS, ASSIGNOR T0 JAI-IN & OLIJIER. ENGRAVING 'COAMPAN'Z A CORPORATION ILLINOIS. y

` Pa'ocnss or PREPARING Eroman on. ENGRAVED PLATES.

To all it may concer/n.' p

Be it known that I, BURGOYNE dorms, aV

citizen of the United States,residing-in the city of Hinsdale, county of 'DupageJwand State of Illinois, have invented new and useful Improvements in the Processes vof Preparing Etched or Engraved Plates, of which the following is a specification.

This invention relates to improvements in the process of preparing etched or'engraved plates, and more especially to the process of preparing a set of plates to be used together in printing in colors on a color printing press, of one of the types in ordinary use. Y

It is well known that when impressions are taken in black and white from a slngle etched plate prepared by` one 0f the Well known processes such as the photo-engrav- 'ing process, or the half-tone process, where it is desired to make certain parts of the impression appear blacker" than other parts, portions of the surface of thetympan roller are raised by pasting on it'small pieces of paper cut in the required shape. These are called make-readies and their effect .isto

cause increased pressure on the paperover certain parts of the printing plate to .make the required impression. It is also well known that where the pr-inting is done in colors by one of the simultaneous processes of printing' in two -or more colors at one operation, by means of a single tympan roller. with the impression rollers surrounding it, it is not feasible to place makereadies over the tympan roller since the high places thus formed would press against all of the impression rollers and spoil the :effect desired. It is therefore necessary in such work to prepare the impression plateswith certain portions of their surfaces slightly raised above the other portions and this invention accordingly relates to a process for thus preparing such plates with portions of their surfaces raised with respect to other portions 4and `their entire surfaces etched or engraved as required for printing from them.

The improved process is illustrated'in the accompanying drawing, in which:

Figure 1 is a view illustrating one of the the rocess.

lhg.'4 2 -is a similar view illustrating the same plate as it appears after a lsubsequent :step in the process.

Fig, l3 is a similar view illustrating the appearance of the .same plate after a fur- 'therstep in the process.

l Fig. is a similar View illustrating the appearance of the finished plate.

5 is a diagrammatic sectional view through asimilar plate showing the raised places on its surface enormously exaggerated for the purpose of better lillustration.

The process consists in'lirst making the requirednumber of photographic negatives accordingto the number ofcolors to be afterward used in lthe printing, the negatives being made through a perforated lscreen on glass' plates in a camera, with means employed to locate each plate exactly in the same place in the camera so that if the glass negatives are afterward superimposed corresponding points in the images will register accurately with each other. Each of these glass negatives is then used to prepare one of the metallic lates, the further process beingthe same or each one of- -the latter and being as follows: The surface of a copper plate is sensitized with a sensitizing solution and upon it is made la print from one of the glass negatives. This print is then developed, or fixed, and eX- amined and the parts of the designselected which it is desired to bring out afterward in denser color than the other parts, 'and these parts of the design are covered with a protecting cover such as asphaltum paint by means lof a brush. The plate is then treated with an acid bath to remove all ofv the sensitizing preparations andthen to a bath in a solution of ferrie chlorid, or its equivalent, to etch or cut down all of its surface except the Y.parts which have been protected by the paint. After this step in the process the plate would appear as shown in Fig. l with portions 1, 2, of its surface SpecificationV of Letters Patent. Patented Aug. 20, 1918. Application led April 20, 1.916.` Serial No. 92,548.

pl-atesas it appears after the first step l :ser

relatively raised and all the other portions of its vsurface lower and perfectly smooth. The paint is then washed off, the entire surface of the plate re-sensitized, and another .as was obtained for the first print.

print made on its surface with the same glass negative; the latter being registered exactly tion and to a bath of ferrie chlorid to etch or cut down all of its unprotected surface. After this stage in the process the plate would appear as in Fig. 2, where the raised portions l and 2 are seen preserved, together with theslightly less-raised portions 3, 4. In this manner the plate may be repeatedly treated to lower its surface, leaving parts of it correspondingly raised to different relative heights according to the strengths of impression afterward desired in the printing process; Fig. 3 illustratino4 the plate after a further treatment to an aci bath and an etchingl bath of yferrie chlorid with protected portions of its surface relatively'raised above the remaining portions.

After'the desired number of treatments to' thus provide the relatively raised portions on its surface the entire plate is finally resensitized, printed and developed, or fixed, and is heated, or burnt as it is technically known in the process, to bake the sensitizing preparation or enalnel with which it has been'prepared; and it is then treated once more to an etching bath of ferrie chlorid, or its equivalent, to eat through the unbaked parts. of the enamel and form the innumerable-small dots or points in its surface which are required forga subsequent printing processthis last step in the process of burning'and etching the plate being performed in the same manner'as has been heretofore in common use.

The plate thus prepared will'present the appearance of Fig. 4 with certain portions of its surface raised with respect to other portions and with respect to each othrr; and with the entire surface etched into the small dots and points which result from the original exposure of the glass plates through a perforated screen. Such a plate in crosssection will also appear as shown diagrammatically in Fig. 5, in which, however, for better illustration the contours are enormously exaggerated. i

` Although the process has been above described particularly for the preparation of onc'of the metal plates, as for example the plate usedA in printing a blue color, itis intended that the same process shall be usedV for preparing eachof the other plates; and if there is a part of the design which must terasse be emphasized byv a relatively stronger mixture of two colors, as for example a green portion, the corresponding parts of the blue plate and the yellow plate must both be raised so that they will afterward cause these two colors to be both emphasized in the same part of the design; whereas if a part of the design to be emphasized in stronger color requires .only one of the primay be used as original plates and from them any number of duplicates made by taking fromceach cop er plate a lead nold and filling this mold y the familiar electrotype, or equivalent process, as is Well n-own.

I claim as my invention:

l. The process of preparing an etchable or engravable plate to receive a design, which consists in first providing a plate with a portion ofits surface relativelyhigher than another portion thereof according to the relative position of the lights and shadows'in the intended design. i

2. The process of preparing an etchable or engravable plate to receive a design, which consists in first acting chemically uponthe surface of a plate to provide portions of the surface which are relatively higher than other portions thereof according to the relative position of the lights' and 4 shadows in the intended design.

3. rIhe process of preparing an etchable o1' engravable pllate to receive a design,

which consists in printing the design upon the surface of a plate, providing portions of the surface with a protecting covering according to the relative position of the lights and shadows in the design, acting upon the unprotected portions of such surface to cut them away, and then reprinting the design upon the plate.

'4. The process of preparing an etchable or engravable plate to receive a design, which consists in ymaking an impression of the design upon a plate by a Vphotographic process, then protecting a portion of the surface by a chemical resisting covering according to the relative position of the lights and shadows in the design, then subjecting the plate tothe action of chemicals to cut away unprotected portions of its surface and then reprinting the design upon the entire surface.

5. The process of preparing an etched or engraved plate which consists in making an portions of its surface, then -reprinting the impression o'f 'a design upon the surface of a design in .the same position upon the surface 10 plate by a photographie process, then p'roand then etching or engraving the design tecting a portion of the surface by a 'ehemiupon the plate. l i

.5 Cal resisting covering -accordin to the rela- In Witness .whereof I have hereunto subtive position of the lights ang shadows in scribed my name this 14th day of April, the desigmthen subjecting the plate to the 1916. l action of achemical to eut away unprotected BURGOYNE J ONES. 

